[Non-carcinogenic health risk assessment of nickel in agricultural products and drinking water in an e-waste dismantling area of Qingyuan City, Guangdong Province]

Vegetables, rice, eggs and drinking water samples were collected from e-waste dismantling area of Qingyuan City, Guangdong Province. Nickel (Ni) was analyzed in each sample, and the non-carcinogenic health [the daily intake (DI) and hazard quotient (HQ)] of each sample was evaluated. In this e-waste dismantling area, the contents of Ni in rice and eggs were (0.46±0.24) and (0.16±0.13) μg/g, which were higher than those in the control area [the contents of Ni in rice and eggs were (0.17±0.03) and (0.02±0.02) μg/g, respectively] (both P values<0.05). The DI values of rice, vegetable, eggs, and drinking water were (3.61-5.86), (1.75-2.99), (0.11-0.24), and (0.08-0.12) μg·kg(-1)·day(-1), respectively. The HQ values were 0.180-0.290, 0.090-0.150, 0.005-0.010, 0.005-0.006, respectively. Although the HQ values of rice, vegetable, eggs, and drinking water were all lower than 1, which was an acceptable level. However, considering the possibility of combined exposure of heavy metals, the non-carcinogenic health risks of Ni in the e-waste dismantling area should still be concerned.

In vitro initial expansion of mesenchymal stem cells is influenced by the culture parameters used in the isolation process

In the last years, there were many studies based on the use of human bone marrow mesenchymal stem cells (hMSCs) in cell therapy and tissue engineering. Although hMSCs can be easily obtained and expanded in culture, a large number of cells are often needed. The expansion of hMSCs depends on the culture conditions, such as media, cell density or culture flasks. Moreover, growth factors are often added to improve cell proliferation. In this study, we compared the effect of two culture media (DMEM and alpha-MEM), two culture flasks (75 or 25 cm2) and two different mononuclear cell seeding densities (1 x 10(4) or 5 x 10(4) MNC/cm2) on the isolation of hMSCs from bone marrow samples and analyzed if the isolation conditions affected the expansion of these cells in the first two passages. Experiments were performed without the addition of exogenous growth factors. Our results showed that alpha-MEM is the optimal culture medium for both, isolation and expansion of mesenchymal stem cells. Moreover, the cell seeding density of 50,000 MNC/cm2 in 25 cm2 culture flasks seems to be the best condition for the isolation step.

Rosiglitazone ameliorates abnormal expression and activity of protein tyrosine phosphatase 1B in the skeletal muscle of fat-fed, streptozotocin-treated diabetic rats

Protein tyrosine phosphatase 1B (PTP1B) acts as a physiological negative regulator of insulin signaling by dephosphorylating the activated insulin receptor (IR). Here we examine the role of PTP1B in the insulin-sensitizing action of rosiglitazone (RSG) in skeletal muscle and liver. Fat-fed, streptozotocin-treated rats (10-week-old), an animal model of type II diabetes, and age-matched, nondiabetic controls were treated with RSG (10 micromol kg(-1) day(-1)) for 2 weeks. After RSG treatment, the diabetic rats showed a significant decrease in blood glucose and improved insulin sensitivity. Diabetic rats showed significantly increased levels and activities of PTP1B in the skeletal muscle (1.6- and 2-fold, respectively) and liver (1.7- and 1.8-fold, respectively), thus diminishing insulin signaling in the target tissues. We found that the decreases in insulin-stimulated glucose uptake (55%), tyrosine phosphorylation of IRbeta-subunits (48%), and IR substrate-1 (IRS-1) (39%) in muscles of diabetic rats were normalized after RSG treatment. These effects were associated with 34 and 30% decreases in increased PTP1B levels and activities, respectively, in skeletal muscles of diabetic rats. In contrast, RSG did not affect the increased PTP1B levels and activities or the already reduced insulin-stimulated glycogen synthesis and tyrosine phosphorylation of IRbeta-subunits and IRS-2 in livers of diabetic rats. RSG treatment in normal rats did not significantly change PTP1B activities and levels or protein levels of IRbeta, IRS-1, and -2 in diabetic rats. These data suggest that RSG enhances insulin activity in skeletal muscle of diabetic rats possibly by ameliorating abnormal levels and activities of PTP1B.

The effects of Chinese herb Angelica in focal cerebral ischemia injury in the rat

This experiment was designed to study the therapeutic mechanisms of Angelica on the focal cerebral ischemia injury of the rat. The ischemic area was determined by TTC stain. And terminal deoxynucleotidyl transferase (TDT) mediated DUTP-biotin nick end labeling (TUNEL) method was applied to detect neuronal apoptosis. The expressions of Bcl-2 and Bax proteins were observed by immunohistochemical staining methods. Results show that the treatment with angelica reduced the volume of cerebral infarction (p < 0.05), and that the number of neuronal apoptosis cells decreased significantly (p < 0.01). Also the expression level of Bax protein decreased (p < 0.01). These results suggest that Angelica can reduce the number of apoptosis cells by decreasing the expression of Bax protein. This is maybe one of the mechanisms of the therapeutic effect of Angelica on focal cerebral ischemia injury.

Effects of an angelica extract on human erythrocyte aggregation, deformation and osmotic fragility

In Chinese traditional medicine, angelica is widely used for its known clinical effects of ameliorating blood microcirculation. But the mechanism of these beneficial effects still remains unclear. In this work the rheological behaviour of human erythrocytes treated by angelica was studied in vitro. Normal RBCs incubated with an angelica extract at different concentrations (5, 10 or 20 mg/ml) for 60 min at 37 degrees C and then their aggregation, deformation and osmotic fragility were measured with different recently developed optical techniques, namely Erythroaggregometer (Regulest, Florange, France), LORCA (Mechatronics, Amsterdam) and Fragilimeter (Regulest, Florange, France). Experimental results show that angelica (20 mg/ml) significantly decreased normal RBCs' aggregation speed (p<0.01) and could inhibit the hyperaggregability caused by dextran 500. However, the strength of normal RBCs aggregates were not influenced by angelica. When a calcium ionophore A23187 (1.9 microM) was used to harden cell membrane, angelica (20 mg/ml) could significantly (p<0.01) protect erythrocytes against the loss of their deformability even it had no effects on normal RBCs deformation. Finally angelica (5 and 10 mg/ml) decreased significantly (p<0.01) normal RBCs osmotic fragility. In conclusion angelica plays a rheologically active role on human erythrocytes, and this study suggests a possible mechanism for angelica's positive effects against certain cardiovascular diseases.

[Protective effect of Angelica on ECV(304) from injury induced by hyperlipidemic serum in vitro]

The aim of this article was to examine the protective effect of Chinese traditional medicine Angelica on human umbilical vein endothelial cells (HUVECs, ECV(304)) from injury induced by hyperlipidemic serum (HLS) and to study the underlying mechanisms. Microstructures of HUVECs were observed by a scanning electron microscope. Spectrophotometer and immunocytochemical methods were used to detect the content of NO in the suspension and expression of ICAM-1, TGFbeta(1), bFGF on the cell surface, respectively. After being incubated with HLS for 24 hours, HUVECs exhibited pronounced morphological changes, such as disappearance of microvilli on the endothelial cell (EC) surface, rupture of cell membranes, etc. Expression of ICAM-l and bFGF in ECs was significantly increased, while expression of TGFbeta(1) and the release of NO from ECs were significantly decreased. All these effects of HLS on ECs can be reversed by Angelica significantly. The above effects of Angelica may be related to its anti-atherosclerotic action.